Re: Where does systemd-logind.service store its stats (e.g. loginctl things)?

On Sat, Jul 4, 2026 at 11:27 AM Chris Green <[email protected]> wrote:
>
> Greg Wooledge <[email protected]> wrote:
> > On Sat, Jul 04, 2026 at 12:49:40 +0100, Chris Green wrote:
> > > This is more out of interest than necessity but I'd like to know where
> > > systemd-logind.service stores its persistent data. E.g. in particular
> > > when I run 'loginctl enaable-linger chris' where is the required flag
> > > set?
> > >
> > > It must be a persistent location as 'enable-linger' obviously survives
> > > a reboot, but I just can't find where it is.
> >
> > I looked at the SEE ALSO section of loginctl(1), and it refers to
> > logind.conf(5).  It also says "See also KillUserProcesses= setting in
> > logind.conf(5)." in the description of the enable-linger option.
> >
> > logind.conf(5) says
> >
> >            /etc/systemd/logind.conf
> >            /run/systemd/logind.conf
> >            /usr/local/lib/systemd/logind.conf
> >            /usr/lib/systemd/logind.conf
> >            /etc/systemd/logind.conf.d/*.conf
> >            /run/systemd/logind.conf.d/*.conf
> >            /usr/local/lib/systemd/logind.conf.d/*.conf
> >            /usr/lib/systemd/logind.conf.d/*.conf
> >
> Yes, I've looked at that too. Most of those locations aren't really
> suitable (obviously the /run ones aren't) but I looked anyway and
> there's nothing of much use.
>
>
> > It also says that KillUserProcess= is an option, and that all options
> > can be configured "in the [Login] section".
> >
> > So, I would check to see whether something has been created in the
> > /etc/systemd/logind.conf.d/ directory.  Failing that, I would look
> > for "[Login]" as a literal string in any file under /etc/.
>
> There's no /etc/systemd/logind.conf.d directory on my systems where I
> have I have set enable-linger. For the other:-
>
>     root@tackpi:~# grep -r '\[login\]' /etc
>     root@tackpi:~#

A stab in the dark using Google AI and the question,“Does systemd use
a database“:

2. systemd-userdbd and systemd-homed (JSON Record Multiplexing)

Modern additions to systemd introduce a concept called the User
Database API.

  * systemd-userdbd acts as a multiplexer for user and group
    definitions using JSON records rather than traditional /etc/passwd
    text lines.

  * It queries files and active services via IPC (Varlink protocols)
    but is not a central SQL-like database.

Jeff